Randomly my computer's HDMI output (running Debian 8) doesn't output anything to HDMI (my screen says "no signal"). Other times it does. The only thing I can say it is that if it works just after boot, it works always, otherwise it doesn't work at all and I have to restart my machine.
I made some research and apparently nothing is wrong:
- I have an NVidia graphical card supporting Optimus technology, so I'm using bumblebee with proprietary nvidia software uninstalled
- lsmod | grep 'hdmi' returns several items:
snd_hda_codec_hdmi 45118 1 snd_hda_codec 104463 5 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_intel,snd_hda_controller snd_pcm 88662 4 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel,snd_hda_controller snd 65244 18 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel
How can I diagnostic what's wrong with my HDMI output?